CELL ASSENBLY OF BASEMENT MEMBRANE IN COCULTURES

点击翻译按钮获取中文摘要

Basement membranes, cell associated heteropolymers, are specialized extracellular matrices and are important for development and maintenance of tissue functions. An in vitro system of epithelial cells and fibroblasts co-culture was used to study the role of cell surface receptors in the assembly of a sub-epithelial basement membrane. A basement membrane was formed only in co-culture although fibroblasts alone synthesize and secret most basement membrane components. When epithelial cells were cultured singly on a type I collagen gel containing basement membrane proteins (laminin, entactin/nidogen), these proteins diffused through the gel and were concentrated in the sub- epithelial region over several days suggesting that these components assembled on selected surface receptors or existing matrix components. Blocking integrin Beta-1 of epithelial cells by a monoclonal antibody caused dramatic effects on C2BBe cell adhesion, basement membrane formation and epithelial polarity. However, the amount of laminin and entactin/nidogen in antibody treated co-culture remained the same as that in control. The results suggest that the assembly of sub- epithelial basement membrane in vivo require interaction between cell surface receptors and matrix components.